It appear that magnesium deficiency plays an important role in the development and progress of depression. Magnesium is an important nutrient neccessary for proper functions of the nervous system and muscle contraction. A legion of related disorders might cripple your spine unless you're well fed on magnesium. I've tried this myself and can attest to it's effects:

http://www.coldcure.com/html/dep.html

Because mental irregularities can arise from an ocean of cross-dependent factors magnesium might not always help, but it seem effective most of the time. Spontanous anxiety used to be an issue for me but when I started on a pill or two of Magnesium Stearat 300mg daily it's gone for good. Magnesium also helps keep your bone healthy as it neutralizes blood PH making it less acid, thus reducing bone loss.

http://www.mdschoice.com/text/abstracts ... gosteo.htm

Overall, proper magnesium intake is a natural alternative to various potentially harmful chemicals, such as anti-depressants. I urge everyone who has depression as an issue to try magnesium first. It migth prove effective - magnesium deficiency among Western countries is more common than you think.